Martin kramer



(No Model.) '3 Sheets-Sheet 1.

M. KRAMER.

SEWING MACHINE.

No. 444,212. Patented Jan. 6,1891.

r I Q a z E\ 1% 1 :0 J: a/ c "g I: Z? e JZ 91 g l/ htwawao gmmtdm 451;; 0'1, M GM; 440/134 (No Model.) 3 Sheets-Sheet 2.

- M KRAMER SEWING MACHINE.

No; 444,212. Patented Jan. 6, 1891.

Wil a b00300 M 1% 1 4 CR5 00.. FHUWUTHIL, WAENINGTON o c (No Model.) 3 Sheets-Sheet 3.

I M. KRAMER.

SEWING MACHINE.

No. 444,212. Patented Jan.6, 1891.

p UNITED STAT-Es PATENT rrwa.

MARTIN KRAMER, OF NEW YORK, N. Y.,ASSIGNOR TO ELI w. BROADBENT,

on SAME PLACE. I

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 444,212, dated January 6, 1891.

Application filed April 25, 1890. Serial No. 349,472; (No model.)

To all 1077,0172 it may concern:

Be it knownthat I, MARTIN KRAMER, of the city and county of New York, in the State of New York, have invented a certain new and useful Improvement in Sewing-lVI-achin es,

of which the following is a Specification.

My invention relates to an improvement in sewlng-machines, and more particularly to the feed and stitch-forming mechanism of a single-thread or loop-stitch machine, the obect being to simplify such mechanisms, materially reduce the friction of the operating parts, and to provide adjustments by which the machine will be adapted to all kinds of work. i

i A practical embodiment of my invention 1s shown in the accompanying drawings, in which- Figure 1 is a View of the machine in front elevation. Fig. 2 is a View of the same in vertical longitudinal section. Fig. 3 is a view in end elevation, showing the work-plate in section for the purpose of more clearly illustrating such a feed mechanism. Fig. 4 is a 2 5 View in end elevation of the right-hand or heel end of the machine. Fig. 5 is a imilar View with certain parts removed to more clearly show the operating mechanism. Fig. 6 is a similar view showing certain parts re- ;o moved and other parts in operative adjustment. Fig. 7 is an enlarged View in detail, showingthe feed-bar at the limit of its forward and upward adjustment and the looper in its position relatively thereto. Fig. 8 is a 5 5 similar view showing the feed-bar at the limit of its reaward adjustment and the looper in its position relatively thereto. Fig. 9 is an enlarged view in detail of the looper-hook.

Similar letters of reference designate corro- 4o sponding parts in all the figures.

A represents the frame of the machine, having the upper branch a and lower branch at; B, the drive-shaft journaled in suitable bearings at the opposite ends of the upper branch a; C, the reciprocating needle-bar seated in adjustable bearings c and driven by a crank b on the end of the drive-shaft B, and D a balance-wheel on the heel end of the drive-shaft, and cl the spool support.

The above-named parts are of substantially the same form and arrangement as the corre sponding parts illustrated and described in Letters Patent No. 404,965, granted to Alfred Faulkner June 11,1889, and need not be more particularly described herein.

The looper in my present improvement is formed by means of a hook E of peculiar construction, fixed on what I am pleased tov term the looper-shaft F, journaled in a hollow shaft, which I shall hereinafter term the feed-shaft F, the latter journaled in suit able bearings at the opposite ends of the lower portion a of the main frame. The looper-shaft F is given a rocking motion by means of an eccentric b, fixed near the heel end of the drive-shaft B. The connection between the eccentric b and the shaft F is made by a longitudinally-reciprocating bar 19 preferably of triangular form, as shown, and seated in or between two adjacent edges of longitudinal guides b one of said guides being adjustable toward and away from the other conveniently by means of set-screws b, which secure it to the frame for taking up any wear. The upper end of the bar b is 5 provided with a loop 12 within which the cam 19 rotates, and the lower end of said bar I) is provided with a lateral and downwardly-extending arm I)", which has a loose connection with an arm b fixed to the shaft F. Said So loose connection may conveniently be formed by providing the arm I) with a slot 1) and the arm I) with a stud b adapted to enter the slot 19 In order to hold the 1000 b out of engagement with the cam 1) during such part of the revolution of the shaft B as is not required to actuate the looper-shaft F and to insure the retention of the hook in po sition to receive the needle through the loop formed thereon, as will be hereinafter more particularly explained, a spring Gr (see Fig.

2) is seated in a recess g at the heel of the frame A in proximity to the reciprocating bar I) and is engaged by a stud or pin g, fixed to the bar 19 the tension of which spring 93 tends at all times to press .the bar toward the upward limit of its stroke.

The looper-hook E is provided with a thin point e, adapted to move forward in close proximity to the needle H between it and the thread which it brings down with. it, and a short distance back from its point said hook gradually increases in thickness at its lower portion, as shown at c, while the thin portion extends to a considerable distance back at the top of the hook, so that an oblique shoulder e is formed across the side of the hook. The effect of this structure is that as the hook moves rearward between the thread and needle it will carry the loop of thread into the bight e of the hook, and because of the thickened portion along thelower edge of the hook will spread the loop of thread, leaving a space between the said thread and the thinner upper portion of the hook in the immediate neighborhood of the shoulder (2 so that as the needle descends, the hook at the same time gradually receding toward the front, its point will follow along the thin portion of the hook near the shoulder c and will pass through the loop which surrounds the hook. Of course itis understood that the rotation of the drivc-shaft B, which reciprocatcs the needle, is so timed withrespectto the rocking of the'looper-shaft by the means which I have particularly described that the hook will ad vance to the rear just as the needle dwells at the lower limit of its stroke, the hook there by receiving the thread onto it and then resting in that position until the needle roturns for the next stitch and then receding toward the front as the needle follows along down the side of its thin portion. 3y this simple arrangementlam enabled to do away with any otherguide than the hook itself, and as this moves through a very short distance of are it follows that its shaft I will be required to make only a very limited rocking movement, and hence the wear from friction will be extremely slight. In connection with such movements of the looper and its shaft the hollow shaft F, within which the loopershaft 1 is seated, is caused by a simple rocking movement to operate the feed as follows: The feed consists of a serrated jaw K, having in its shank a vertically-elongated slot- 7:, through which by means of a set-screw 7. it is secured to the feed-bar l. in vertical adjustment. Such vertical adjustment of the feed-jaw is very important, in that it admits of throwing the serrated face of the jaw upwardly and downwardly through the worktable I, so as to bring it into a stronger or lighter engagement with the goods, as may be desired, and thus feeding heavy goods positively along the table and at the same time providing against defacing thinner and more delicate goods. The feed-bar L is provided at or nearits rear end with an elongated slot Z, through which by means of a screw Z it is pivotally secured to a stationary support M at the end of the lower branch ct in such a manner as to have a limited longitudinal movement toward the front and rear of the machine. To further keep it in its position, a guide-lip Z is secured to said support M and overlaps the said feed-bar near its front end. The forward and backward longitudinal movement of the feedbar, and hence the feed, is effected by means ishaft l3 and connected with a laterally-extending arm 21, fixed on the hollow shaft 1 at the heel end of the main frame by a connecting-rod 72, provided at one end with a strap n su rronndin g the eccentric N, and at the opposite end with a clip a, adapted to embrace and slide along the said arm n. The connectingrod n is loosely connected with the clip a, and the said clip is provided with a set-screw a for the purpose of fixing it to the arm a at any point desired to give the shaft 1* a greater or lesser throw in its rocking movement, and hence the feed-bar and feed a greater or lesser throw forward and backward to increase or diminish the length of stitch. It will be obversed that by pro vidin g the arm it with ascale of an y ordinary and well-known form thelength of stitch may be varied with the greatest precision and with great facility. The upward movement of the feed'bar L is effected by means of a cam 0, fixed on the looper-shaft F in proximity to the end of the hollow shaft I and preferably immediately beneath the feed-bar L. The movement of the cam O is so timed with respect to the rocking of the shaft F that it will engage and lift the feed-bar when the latter is at or near the forward extremity of its throw and will hold it elevated until it nearly or quite reaches the rearward limit of its throw, when it again recedes and allows the feed-bar to drop into position to move forwardly out of contact with the goods. By the 1 above arrangement the feed is effected with but a very slight rocking movement of the shaft F, and hence very slight frictional wear.

In order to provide for the taking up of wear upon all parts where it is feasible, I form the pressure-foot bar P triangularand mount it in bearings 1), one section of whichI make adjustable, in a manner quite similar to that described in connection with the longitudinally-reciprocating bar D hereinbefore referred to, at the heel end of the frame, and in a manner quite similar to that in which the needle-bar is mounted. As thus constructed a person of ordinary skill may so manipulate the parts as to take up wear, regulate the stitch, and adjust the feed to suit all grades of goods being sewed.

It is evident that slight changes might be resorted to in the formation and arrangement of the several parts described without dcparting from the spirit and scope of my invention. Hence I do not wish to limit myself strictly to the construction herein set forth; but

\Vhatl claim as my invention, and desire to secure by Letters Patent, is

1. In a sewing-machine, the combination, with a reciprocating needle, of a rock-shaft, a looper fixed thereon, a drive-shaft, and a IIL.

bar having a longitudinally-sliding movementin a fixed line and connecting the drive-shaft and rock-shaft, through which a rocking motion is transmitted to the rock-shaft, substantially as set forth.

2. In a sewing-machine, the combination, with a reciprocating needle, a rock-shaft, a looper on the rock-shaft, a drive-shaft, anda cam on the drive-shaft, of a bar having a 1ongitudinally-reciprocating movement in a fixed line, said bar being provided at one end with a loop to embrace the cam and at the opposite end with an arm eccentrically connected with the rock-shaft, substantially as set forth.

3. In a sewing-machine, the combination, with two concentric rock-shafts, one for actuating the looper and one for actuating the feed, of a feed-bar support located at one side of said actuating-shafts, a feed-bar having a limited longitudinal sliding movement on its support and also a swinging movement thereon, a cam on the looper-actuating shaft in engagement with the feed-bar to give it its swinging movement, and an arm on the feed-actuating shaft engaged with the feed-bar, so as to admit of a free movement of the bar toward and away from the actuating-shaft and at the same time cause the feed-bar to move longitudinally with the swinging of the arm, the engagements of the cam and arm on the two concentric shafts with the feed-bar being at points intermediate of the feed-bar support and its free end, substantially as set forth.

MARTIN KRAMER. Witnesses:

FREDK. HAYNES, F. G. BARRY. 

